Without protection, data stored on storage devices (e.g., hard disks, tapes, non-volatile memories, and other storage devices) is basically accessible to anyone with access to the storage devices. In particular, data accessible by way of a computer network, such as network storage, is especially vulnerable to unauthorized access, modification or deletion.
To protect the stored data, the stored data may be encrypted. In general, encryption transforms the stored data using an algorithm to make the stored data unreadable to anyone except those possessing information that may be used to decrypt the data. Such information is typically stored separately from the storage devices and can be lost, for example, from data corruption or when the storage device is redeployed to a different storage system. Without such information, the stored data on a storage device cannot be recovered.